Keep On The Sunny Side”, that Carter Family folk anthem of American optimism, suggests why we New Orleanians are so misunderstood in our own country. Here in The Big Easy, natives hug the shady side of life. Gathering in pools of shadow beneath our wrought-iron balconies, we shake our heads as tourists slog through brutal midday sunshine across the street. In sweltering New Orleans we know you needn’t fear darkness: it’s the sun that will kill you.

So what visitors take as our dark depravity is less an expression of our character than our climate. Of course, climate breeds culture and when you grow up in the dark, playing in the cool of the evening until midnight you learn early on, as Mr Roosevelt Sykes sang until his death in New Orleans in 1983, that “night-time is the right time”.

Night-time is certainly the right time to hear the most distinctive music of any city on the continent. But if you ask a local musician what sets our music apart, don’t expect an exposition on major versus minor keys.

According to Mr Sammie “Big Sam” Williams, “To play our music, you got to live here. Embrace the city, embrace the culture.” Mr Williams fronts Big Sam’s Funky Nation, one of a number of New Orleans bands led by a trombonist. “When I started out, everybody wanted to be a trumpeter. These days, when we see a trumpet player, we tell ’em, ‘You’re just a squirrel trying to get a nut.’” Mr Williams calls his music “Noladelic funk” (a combination of Nola, short for New Orleans, Louisana, and psychedelic), and his roots run deep in the city. The great-grandson of jazz progenitor Mr Buddy Bolden, he proposed to his wife on stage during a New Orleans Jazz Festival performance. (When I mention that I’ve read he proposed on his knees, he corrects me: “Just one knee.”)

Mr Williams exemplifies how life and music intertwine in New Orleans. He and his high-school classmate and fellow trombonist Mr Walter Ramsey were founding members of The Stooges, one of the city’s most popular bands. Though his first instrument is the ’bone, as he calls it, Mr Ramsey picked up the sousaphone after the band’s regular tuba player quit the night before a performance. Since 1996, he has led The Stooges in countless parades in town, performances around the country and even a US State Department tour of Pakistan, Kyrgyzstan and Tajikistan. “We were the first brass band they ever heard,” he says.

When I ask how a little city like New Orleans produces so many great musicians, Mr Ramsey explains, “You grow up here with music in the street. So a kid picks up a bottle and starts to keep time against the curb [kerb].” That’s how it happened to him. While he was still in elementary school, he saw the Rebirth Brass Band and decided that’s what he wanted to do. “New Orleans is special,” he says. “We have a lot of energy – a good vibe, a party vibe, a heavy vibe. And we all about the spirit of the people.” When I ask about the music itself, he says it’s funk, jazz, R&B, gospel, rock and blues. “But no one else can put it together like New Orleans. Something about us. Must be the water.”

Grammy award-winning trumpeter Mr Irvin Mayfield Jr has a different way of describing the sound. “What is a city?” he asks. “It’s an idea answered by the people who live there, the people who love it. New Orleans music is the same thing. It’s an idea, kind of like New Orleans food. You keep adding to the pot, but when do you get to where it’s not gumbo any more?” Fluent in the history of the city’s music, he traces it back to Messrs Jelly Roll Morton and Sidney Bechet and the Caribbean influences of Jamaica, Honduras and Cuba. His own career is just as international. Mr Mayfield Jr has performed on four continents in the past four months. But his commitment is to his hometown where he’s just opened the Peoples Health New Orleans Jazz Market, a community centre that makes a further nod to the origins of New Orleans jazz, The Bolden Bar.

“Nothing is smooth or straight down here,” says Mr Young of New Orleans. “That terrain adds to our dance”

Another native New Orleanian, Big Chief Mr Alfred Doucette of the Flaming Arrows, a Mardi Gras Indian tribe, owned nightclubs, trained thoroughbreds, built racing cars and now makes a living as a master carpenter. He explains the African-American tradition of donning extremely elaborate beaded and feathered Indian costumes for Mardi Gras as a homage to the Native Americans who sheltered runaway slaves. “Back in the day, Indians thought the black man was sacred,” he says. Famed as a beader of such costumes and the leader of the Flaming Arrows, Mr Doucette achieved late fame for his songs. “The music is a gift,” he says. “Like I always wanted to sing, but I never did. Then I get to be 60 years old and “Marie Laveau” [his first hit] came into my life. Three nights in a row these words come into my head. The fourth day I was singing the song, the whole entire song. And that’s how I got started.”

Mr Darryl “Dancing Man 504” Young got started after the collapse of the levees in the wake of Hurricane Katrina, which flooded New Orleans in 2005. He returned home from Colorado and founded the Heal 2 Toe programme to get kids dancing again. The disaster left the city in ruins, but Mr Young says it’s good that the streets are still in disrepair. “Nothing is smooth or straight down here,” he says. “That terrain adds to our dance – to give us that skip or that jump – because second lining [dancing] is all about stepping over obstacles.” He traces the dance style’s origins back to Haitian carnival processions, but notes that the brass bands that lead our second-line parades were a New Orleans addition.

From the Dirty Dozen Brass Band to the Soul Rebels and Bonerama, New Orleans brass bands have put “feet in the street” for decades, but the Rebirth Brass Band brought a new generation to the tradition in 1983, discarding the white shirts and “milkman hats” of older bands in favour of jeans and baseball caps. The beat was the same as it had always been, but Rebirth played new songs to that beat, whether funk or hip-hop.

Trombonist and Stooges Brass Band leader Mr Walter Ramsey says of New Orleans, “You grow up here with music in the street”

Trumpeter and vocalist Mr Kermit Ruffins, a founding member of Rebirth, has just flown in on the red-eye from Houston and is settled on a bar stool at his club on North Claiborne Avenue. His barbecue trailer is resting outside the front door in blazing sunlight, but New Orleans bars are so dark that 10.00am feels like midnight inside Kermit’s Treme Mother-in-Law Lounge.

A couple of regulars wander in wearing New Orleans Saints jerseys. “Gonna beat dem Falcons,” one of them assures us about that night’s football game at the Superdome against undefeated Atlanta. “Yeah, you right,” somebody answers, not looking up from his drink.

Trumpeter Mr Kermit Ruffins is a founding member of the Rebirth Brass Band

The interior of Kermit's Treme Mother-in-Law Lounge

“Music and food go hand in hand,” he says. And he should know – his current band is called the Barbecue Swingers and he’s as well known in town for his stewed rabbit as he is for his music. Playing himself in Treme, the long-running HBO series, he sums up an unusual attitude towards ambition and fame when another character challenges him:

“Kermit, is all you want to smoke weed, barbecue and stay in New Orleans for the rest of your life?”

“That’ll work,” he replies without hesitation.

When I ask him about that scene, he smiles. “Every night on stage I say the same thing: ‘I’m the world’s most happy creature.’” And the whole city feels the same way that evening when the Saints beat the Falcons 31–21.

Like Mr Ruffins, Mr Joe Krown finds, “the music and food thing related. The chefs and the musicians both are always looking to add something unique to what’s traditional.”

Mr Joe Krown in front of his piano at Le Bon Temps Roulé on Magazine Street

Having played with Messrs Chuck Berry, Bo Diddley and a host of other superstars, Mr Krown found his way to New Orleans in 1992 for a permanent job as keyboard player for Mr Clarence “Gatemouth” Brown and wound up, three years later, opening Mr Eric Clapton’s US tour with Mr Brown. But Mr Krown turns down most out-of-town gigs these days. “I’d rather wake up in bed next to my wife in the morning.”

Leaning against his piano, he shrugs, “I came to New Orleans and found what I was looking for. It’s got its own culture, its own food, its own music – and its own standards for drinking.”

He credits a New Orleans legend, Professor Longhair, for introducing Afro-Cuban syncopation to the boogie-woogie and barrelhouse piano-playing popular in the city. But like the local cuisine, “It’s got its own flavour,” he admits.

After Hurricane Katrina, Mr Young set up the Heal 2 Toe dance programme

While Mr Krown likes to play close to home at Le Bon Temps Roulé on Magazine Street, he joins Mr Russell Batiste Jr and Mr Walter “Wolfman” Washington at the Maple Leaf Bar on Sunday evenings.

The first thing that strikes you about Mr Washington is his smile. How can he possibly fit all those teeth inside his mouth? And those teeth do more than just smile.

Having picked up the trick from Mr Jimi Hendrix, the 71-year-old musician flips his flat cap around on stage so the brim won’t interfere when he starts plucking solos with his teeth. From down in the audience, it looks as if he’s kissing his guitar while he draws sweet moans from an instrument he started playing nearly 60 years ago.

Grammy Award-winner Mr Mayfield Jr has performed on four continents in the past four months

Like many New Orleans musicians, his classrooms were the clubs around town, where he heard generations of local legends play. “An old friend of mine, Gatemouth Brown, told me one day, he say, ‘Walter, you really don’t need to know scales. You just need to know music. How it sound. If it sound to you good, play it.’”

Around midnight in The Big Easy, listening to home-grown bands “play it” and fill the humid darkness with a throbbing music that’s the heartbeat of New Orleans, you begin to get an idea of how such a hot city can be so downright cool.